Internal combustion engine



Oct. 11,- 1932. w. R. GRISWOLD 1,882,281

INTERNAL COMBUSTION ENGINE a lf'iled Sept, 23. 1930 Patentecl a. 11,1932 UNITED STATES PATENT! orrica WALTER R. GBISWOLD, OF DETROIT,MICHIGAN, ASBIGNOR TO PAGKARD MOTOR CAB COMPANY, OF DETROIT, MICHIGAN, ACORPOBATIOQN" OI HIOHIGAN INTERNAL COMBUSTION ENGINE Application filedSeptember 28, 1980. Serial No. 488,881.

This invention relates to internal combustion engines and moreparticularly to means 'It has for one of its objects to provide a simpleand effective device to' damp such torsional vibration, in which thedamping effect is secured partly by mechanical friction,

and partly by internal molecular friction or hysteresis.

vide a vibration damper of the character designed having enclosedresilient means for increasing the mechanical friction damping,

18] the friction surfaces being enclosed and protected by the hysteresismeans.

, Another object of the invention is to provide a vibration damperhaving cooperating friction members, the friction surfaces of '20 whichare enclosed in rubber, provided with spring means for increasing thecontact pressure between said surfaces.

A further object of the invention is to provide a vibration damperhaving both mei '35 chanical friction and hysteresis damping devicesassembled in a unit adapted to support an inertia member, and havingdevices car-.

- ried bythe inertia member to increase the damping friction of saidmechanical devices.

Other objects of the invention will appear from 'the followingdescription taken in connection with the drawing, which forms apart ofthis specification, and in which:

Fig. 1 is a longitudinal vertical section through part of an internalcombustion engine provided with a vibration damper constricted inaccordance with this invention, In

Fig. 2 is a view to a larger scale in front elevation and partiallybroken away in several sections, designated by the arrows A, B, C, D andE, which sections are respectively taken substantially on thecorresponding lines A, B, C, D and E of Fig. 1.

Referring to the drawing; in Fig. 1 at- 10 is represented the crank caseof an internal combustion engine, having a lower cover or oil pan 11 andprovided with transverse .webs, such as shown at 12. These webs sup- 0port suitable aligned bearings 13 for an en- 18' may be keyed orotherwise secured as in- Another object of the. invention is to proginecrank shaft 14, which has the usual integral cranks 15, each of which isconnected by a connecting rod 16 to a piston mounted in one ofthe'engine c linders. The piston and cylinder are not s own in thedrawing, but are of usual cohstruction. Forwardly ofthe first bearing13, the crank shaft 14 is preferably formed witha reduced portion 17 onwhich a gear or chain sprocket dicated at 19, and used to drive the en ecam shaft or other engine accessories, w 'ch arenot shown in the drawinForwardly of the sprocket 18, the crank s aft is preferably furtherreduced in section as shown at 21, and pro ects through a suitableOpening 22 in the front wall of the crank 'case'10.

The damping means 'of this invention is Illustrated as mounted at oradjacent the end of the crank shaft 14. It comprises a supportingportion or'hub 23, keyed or other-. wise rigidly secured to the crankshaft on the reduced portion 21 thereof, as indicated at 24, which hubhas a radially disposed integral flange 26. Surrounding the hub 23 andconcentric with the crank shaft axis is a weight or inertia member 27,formed in two parts, each of which has a rim portion 28 and a webportion 29, these portions being removably secured together in anyconvenient manner as by clamp bolts 31. These members, the hub 23 andthe inertia member 27, constitute the relatively movable dam r members,between and to which the damping devices are connected. I

The mechanical friction damping means comprises a pair of annularfriction devices I or disks 32 which surround the hub 23 on either sideof, and in frictional contact with the side faces of the hub flange 26.These disks are also in contact with members which are connected to andshare the motion of the inertia member 27 and whichfare shown ascomprising a pair of friction plates 33,- the outer edges of which areclamped between the J parts of the inertia member 27. For this purposethey are separated at their eriphery by a circumferential spacin mem'er' .34, substantially of the same thickness as the combinedv thicknessofthe flange 26 -1 and the disks 32. In this way the plates are ri idlyconnected to the inertia member 27 and are disposedin parallel relationon either side of the flange 26. *It will be evident that the frictiondisks 32 are thus subjectedto a rubbing action caused by relathemovement between the plates '33 and-the flange 26, and accordingly causemechanical friction and hence damping.

The flange 26 is provided with a circular row of axially disposed pins36, which are preferably. permanently secured thereto by upsettingflanges thereon as clearly shown in Fig. 1. The oppositely disposed endsof the pins 36 project into circular recesses 37 formed in the webportions 29 of the inertia member 27 Disposed around the hub 23 oneitherside of the flange 26, and in contact with the plates 33 is anannular ring 38 of her, or any other suitable material which issubjected to a considerable hysteresis loss when put through a cycle ofcompression and expansion. This rubber member 38 constitutes thehysteresis damping member of this invention. It is provided at spaced intervals with circular projections or knobs 39, which are adapted tosurround and tightly embrace the pins 36, and to project into therecesses 37. These members 38 are preferably permanently secured to thefriction lates 33 the pins 36, the flange 26 and the hub member 23, asby being vulcanized thereto, but are not-secured in any way to theinertia members 29 except by being compressed therebetween. I

The rings 38 are also provided with. a circular row of holes or cut-awayportions 40,-

disposed between adjacent pins 36, through which holes portions of theouter surface of the plates 33 are exposed. a The web portion 29 of each.of the inertia members is formed with axially disposed cylindricalrecesses 41, which open inwardly or toward the .plates 33, arranged ina. circular rowintermediate the pins 36and each coaxial with one of theholes 40. Fitted in each of these recesses is a suitable compressioninember such as a coil spring 42,- which springs bear at their ends onthe exposed portions of the plates 33, passing for this purpose throughthe hole 40. In this way the plates 33 areurged toward the flange 26,1ncreasing the pressure on both faceson the "friction disk [32, andwithit the glampin'g friction.

M .It will be evident that upon relative moveinentbetwe'en theinertiamember 27and the haft with its hub member 23, a part of thePatent is "rubber members, and more especially the knobs 39 thereof,willbe forced to partake of the movement of the shaft through the flange26 and the pins 36, while other portions of these-rubber members will becompelled to move with the-inertia member through-the reelasticallydeformable material such as rub-.

parentthat changes may be made therem cesses or depressions 37. Thus itis clear that these rubber members will be considerably distorted,causin a considerable loss of energy by hysteresls or internal friction,with resulting damping.

The rubber members 38 with their lugs 39. also serve other purposes.Being possessed of considerable resilience they continuously exert apressure tending to return the inertia member 27' to its neutralposition with respect to the hub 23, thus acting to restore the deviceto-its original condition after any displacement thereof caused byvibration.

Also, since the friction disks 32 and their cooperating frictionsurfaces are completely enclosed within the elastic members .38, thesesurfaces are thoroughly protected from moisture, dirt, oil and otherforeign matter affecting their friction values. To complete theenclosure of the friction surfaces, an additional peripheral strip orcover rubber 43 may be vulcanized between the plates 33. Because of thisprotection, thefriction, and accordingly the damping effect at anyarticular engine speed remains substantlally constant, beingunaflfectedby conditions, extraneous to the damper. a

It will be observed that the damper hub and its flange and pins theplates 33, the friction disks 32, and the rubber elements, :53 may beconveniently permanently secured into an assembled .unit, the partsbeing retained in position by reason of the rubber which forms thecover. This unit can be easily replaced in the event of wear Tm: oraccidental damage, it being only necessary to clamp the unit in placebetween the halves of the inertia member, and secure these upon the endof the shaft in any convenient way. As'illustrated, this is accom- 5plished by means of a nut 44, which may also a e used to retain on theshaft any necessary driving member, such'as the fan pulley 45. Thefriction'disks 32 are thus permitted to float in frictional engagementwith and between the cooperating flange and the friction plates, whilecompletely enclosed inlthe rubber damping member 38.

-VVhile-as pec1fic embodiment ofthe invention has been herein described,which is deemed'to be new and advantageous and may be specificallyclaimed, it is not to be under-. stood that the invention is limited tothe exact details of the construction, as it will be apiit 220 withoutdeparting from the spirit or scope ofithe invention, A I Havin thusdescribed the invention, what isclaime and desired to be secured byLetters -12: A'vibrationfdamperfor a shafthavin an inertia membermovable relatively to sai shaft, elastically deformable means, frictionmeans substantially covered'by said deformable means and associatedwiththe shaft and 20 -1,eea,aa1 I 3 the inertia member to resistrelative-move-.

. inertia mem r'for resistin relative movement of the latter axiallyposed springs on the inertia mem r to increase the friction of. thefriction means, and elastically deformable means adapted to cooperatewith sa1d inertia member to enclose the friction means and said springs.

'3. A vibration damper for a shaft having a hub member provided with aflange, friction devices engaging said flange, friction plates enga 'ngsaid riction devices, and inertia mem ier clam ed on said frictionplates and movable relatively to said shaft, said inertia member havingaxially disposed recesses arranged in a circular row, springs seated insaid recesses and engaging the friction plates to ensure intimateengagement between the friction devices and the flange and said plates,and rubber means vulcanized to said plates and hub and engaging saidinertia member to enclose the friction devices and springs.

4. A vibration damper for a shaft having a hub member provided with aflange, friction devices engaging said flange, friction 35 platesengaging said friction devices, resilient .cover means for said frictiondevices carried by said plates and hub, an inertiamember having twoannular parts clamped on said plates, and springs carried by the inertiamember for applying pressure between the friction devices, said platesand said hub.

5. A vibration damper for a shaft having a flange carried by the shaftand an inertia member movable relatively thereto, friction- 43 meanscomprising plates carried by said inertia member, and friction "devicesdispoged between said plates and the flange, coil springs'carried by theinertia member and axially en agin said plates to increase the friction'e ect 0 said friction means, and resilient rubber means permanentlysecured to the plates and connected to. the inertia member to yield inresponse to relative movement between the shaft and the inertia member,

. said rubber means forming with the plates and the inertia member anenclosure for said spring.

6. vibration damper for ashaft havin an inertia member movablerelatively to the so shaft, friction means associated with the shaft andinertia member to resist relative move- .ment of theigtter, elasticmeans deformable 1n response prising a c or for said friction means, and

spring means co-acting with said friction said relative movement 1commeans to increase the friction developed thereby.

7. A vibration damper for a shaft having an inertia member movablerelativel to the shaft, contacting friction members 'etionally connectedwith said shaft and connected to said inertia member respectively,elastically deformable means forming a cover for said friction members,and 5 rings for mcreasing the contact pressure tween said frictionmembers.

8. In a vibration dam r for a rotatable shaft, the combination with aninertia member movable relatively to the shaft, of means comprising anelasticall deformable element interposedbetween sai inertia member andsaid shaft and serving to resist relative movement thereof, meanswhereby said deformable element is subjected both to shear and com-' I Ipression stresses on relative movement of said a inertia member andshaft, and spring ressed means extending within said deforma le ele mentand assoclated with said shaft and inertia member for frictionallyretarding relative movement of the latter. y y

9. In a vibration damper for a rotatable shaft, the combination with aninertia member movable relatively to'the shaft, of an elasticallydeformable element connecting said inertia member and said shaft forrotation while permitting slight relative move ment thereof, saidelement being'o ratively connected to said member-and sai shaft atspaced points,-whereby relative movement of the member and shaft willapply shearin 10 stress to said element, and being interpose betweenportions of said'member and shaft adjacent as regards the shaft axis,whereby relative movement of the member and shaft will apply compressivestress to said element and means comprising friction elements andsprings acting to increase the friction therebetween extendin withinsaid deformable element and associated with said shaft and inertiamember for frictionallyretarding 110,

relative movement of the latter.

In testimon whereof I aflix my signature. viALTEn a. GRISWOLD.

